Separation of Palladium from Alkaline Cyanide Solutions through Microemulsion Extraction Using Imidazolium Ionic Liquids
In this paper, three imidazolium-based ionic liquids, viz., 1-butyl-3-undecyl imidazolium bromide ([BUIm]Br), 1-butyl-3-octyl imidazolium bromide ([BOIm]Br), and 1-butyl-3-hexadecyl imidazolium bromide ([BCIm]Br), were synthesized. Three novel microemulsions systems were constructed and then were us...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-06-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/24/13/10709 |
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| author | Hui Deng Chali Liu Xin Xu Yuanyuan Wu Muhan Chen Zhangjie Huang |
| author_facet | Hui Deng Chali Liu Xin Xu Yuanyuan Wu Muhan Chen Zhangjie Huang |
| author_sort | Hui Deng |
| collection | DOAJ |
| description | In this paper, three imidazolium-based ionic liquids, viz., 1-butyl-3-undecyl imidazolium bromide ([BUIm]Br), 1-butyl-3-octyl imidazolium bromide ([BOIm]Br), and 1-butyl-3-hexadecyl imidazolium bromide ([BCIm]Br), were synthesized. Three novel microemulsions systems were constructed and then were used to recover Pd (II) from cyanide media. Key extraction parameters such as the concentration of ionic liquids (ILs), equilibration time, phase ratio (R<sub>A/O</sub>), and pH were evaluated. The [BUIm]Br/n-heptane/n-pentanol/sodium chloride microemulsion system exhibited a higher extraction percentage of Pd (II) than the [BOIm]Br/n-heptane/n-pentanol/sodium chloride and [BCIm]Br/n-heptane/n-pentanol/sodium chloride microemulsion systems. Under the optimal conditions (equilibrium time of 10 min and pH 10), the extraction percentages of these metals were all higher than 98.5% when using the [BUIm]Br/n-heptane/n-pentanol/sodium chloride microemulsion system. Pd(CN)<sub>4</sub><sup>2−</sup> was separated through a two-step stripping procedure, in which Fe (III) and Co (III) were first separated using KCl solution, then Pd(CN)<sub>4</sub><sup>2−</sup> was stripped using KSCN solution (separation factors of Pd from Fe and Co exceeded 10<sup>3</sup>). After five extraction–recovery experiments, the recovery of Pd (II) through the microemulsion system remained over 90%. The Pd (II) extraction mechanism of the ionic liquid [BUIm]Br was determined to occur via anion exchange, as shown by spectral analysis (UV, FTIR), Job’s method, and DFT calculations. The proposed process has potential applications for the comprehensive treatment of cyanide metallurgical wastewater. |
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| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-11T01:39:16Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
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| series | International Journal of Molecular Sciences |
| spelling | doaj.art-9c420df4a3fd44d6beaa755d83a87c2f2023-11-18T16:42:21ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672023-06-0124131070910.3390/ijms241310709Separation of Palladium from Alkaline Cyanide Solutions through Microemulsion Extraction Using Imidazolium Ionic LiquidsHui Deng0Chali Liu1Xin Xu2Yuanyuan Wu3Muhan Chen4Zhangjie Huang5School of Chemical Science and Technology, Yunnan University, Kunming 650091, ChinaSchool of Chemical Science and Technology, Yunnan University, Kunming 650091, ChinaSchool of Chemical Science and Technology, Yunnan University, Kunming 650091, ChinaSchool of Chemical Science and Technology, Yunnan University, Kunming 650091, ChinaSchool of Chemical Science and Technology, Yunnan University, Kunming 650091, ChinaSchool of Chemical Science and Technology, Yunnan University, Kunming 650091, ChinaIn this paper, three imidazolium-based ionic liquids, viz., 1-butyl-3-undecyl imidazolium bromide ([BUIm]Br), 1-butyl-3-octyl imidazolium bromide ([BOIm]Br), and 1-butyl-3-hexadecyl imidazolium bromide ([BCIm]Br), were synthesized. Three novel microemulsions systems were constructed and then were used to recover Pd (II) from cyanide media. Key extraction parameters such as the concentration of ionic liquids (ILs), equilibration time, phase ratio (R<sub>A/O</sub>), and pH were evaluated. The [BUIm]Br/n-heptane/n-pentanol/sodium chloride microemulsion system exhibited a higher extraction percentage of Pd (II) than the [BOIm]Br/n-heptane/n-pentanol/sodium chloride and [BCIm]Br/n-heptane/n-pentanol/sodium chloride microemulsion systems. Under the optimal conditions (equilibrium time of 10 min and pH 10), the extraction percentages of these metals were all higher than 98.5% when using the [BUIm]Br/n-heptane/n-pentanol/sodium chloride microemulsion system. Pd(CN)<sub>4</sub><sup>2−</sup> was separated through a two-step stripping procedure, in which Fe (III) and Co (III) were first separated using KCl solution, then Pd(CN)<sub>4</sub><sup>2−</sup> was stripped using KSCN solution (separation factors of Pd from Fe and Co exceeded 10<sup>3</sup>). After five extraction–recovery experiments, the recovery of Pd (II) through the microemulsion system remained over 90%. The Pd (II) extraction mechanism of the ionic liquid [BUIm]Br was determined to occur via anion exchange, as shown by spectral analysis (UV, FTIR), Job’s method, and DFT calculations. The proposed process has potential applications for the comprehensive treatment of cyanide metallurgical wastewater.https://www.mdpi.com/1422-0067/24/13/10709microemulsionsionic liquidsmetal cyanidespalladium |
| spellingShingle | Hui Deng Chali Liu Xin Xu Yuanyuan Wu Muhan Chen Zhangjie Huang Separation of Palladium from Alkaline Cyanide Solutions through Microemulsion Extraction Using Imidazolium Ionic Liquids International Journal of Molecular Sciences microemulsions ionic liquids metal cyanides palladium |
| title | Separation of Palladium from Alkaline Cyanide Solutions through Microemulsion Extraction Using Imidazolium Ionic Liquids |
| title_full | Separation of Palladium from Alkaline Cyanide Solutions through Microemulsion Extraction Using Imidazolium Ionic Liquids |
| title_fullStr | Separation of Palladium from Alkaline Cyanide Solutions through Microemulsion Extraction Using Imidazolium Ionic Liquids |
| title_full_unstemmed | Separation of Palladium from Alkaline Cyanide Solutions through Microemulsion Extraction Using Imidazolium Ionic Liquids |
| title_short | Separation of Palladium from Alkaline Cyanide Solutions through Microemulsion Extraction Using Imidazolium Ionic Liquids |
| title_sort | separation of palladium from alkaline cyanide solutions through microemulsion extraction using imidazolium ionic liquids |
| topic | microemulsions ionic liquids metal cyanides palladium |
| url | https://www.mdpi.com/1422-0067/24/13/10709 |
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